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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link rel="stylesheet" href="css/index.css">
    <script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
</head>

<body>
    <div class="content">
        <div id="list">
            <img src="images/01.png" alt="">
            <img src="images/02.png" alt="">
            <img src="images/03.png" alt="">
            <img src="images/04.png" alt="">
            <img src="images/05.png" alt="">
        </div>
        <button id="prev"></button>
        <button id="next"></button>
        <div id="btns">
            <span class="current"></span>
            <span></span>
            <span></span>
            <span></span>
            <span></span>
        </div>
    </div>
    <script>
        var index = 0;
        $("#next").click(function(){
            index++;
            if(index>4){
                index = 0;
            }
            animate(index)
            console.log(index)
        })
        $("#prev").click(function(){
            index--;
            if(index<0){
                index = 4;
            }
            console.log(index)  
            animate(index)        
        })
        $("#btns span").click(function(){
            index = $(this).index();
            animate(index)
        })
        function animate(index){
            $("#list img").eq(index).fadeIn().siblings().fadeOut();
            $("#btns span").eq(index).addClass("current").siblings().removeClass("current")
        }
    </script>
</body>

</html>